This invention generally relates to a device or bracket to be associated with motor vehicle wheels in general to support measuring instruments, for example the heads with which vehicle attitude checking systems are provided.
The devices of known type generally comprise a frame which is provided on one side with movable clamps to grip the wheel rim edge, and on the opposite side, on the barycentric axis, with a pin on which the measuring instruments or heads are suspended. The movable clamps are supported by the frame such that they always move by the same extent with respect to the frame centre, i.e. they always lie on a circumference of predefined diameter having its centre on that of the pin support frame.
When the device is associated with a wheel rim, the clamps grip the wheel rim bead retention flange, their ends being inserted below the edge of the tire.
One of these devices is fully described in Utility Model No. 224605 in the name of the same Applicant, to which reference should be made for a complete description.
Such known devices are suitable for wheel rims on which tires of traditional type are mounted, but cannot be used on wheel rims carrying tires of the new generation, usually known as run-flat tires, which can be used over long distances even when deflated. By way of example, these new tire types include that produced by the Michelin Co. with the name of SYSTEM PAX.
With wheels carrying such tires, the tire edge is perfectly flush with the wheel rim edge, there therefore being no space for coupling the clamps to the wheel rim.
Another problem arising with devices or brackets of known type derives from the fact that they can damage the wheel rim, particularly if this is of light alloy, and especially if painted.
The object of this invention is to overcome the aforesaid drawbacks by means of a simple and rational solution.
The invention attains said object by a device for supporting attitude checking heads and sensors for motor vehicles in general which can be coupled to any type of wheel rim, independently of the type of tire mounted thereon.
Specifically, the device of the invention comprises a central member, such as a disc, provided on one side with the support pin for the measuring heads, and on the opposite side with self-centering means carrying elements for engaging structural parts of the wheel rim which lie on a circumference coaxial therewith, and means for operating said self-centering means.
According to a preferred mode of implementing the invention, said self-centering means consist of at least three levers hinged together and to suitable operating means able to rotate them in the same direction through the same extent.
At their end, said levers carry means for coupling them to the central hole of the wheel rim or, alternatively, to the heads of the bolts which fix it to the vehicle, or to the holes through which said bolts pass.
The special characteristics of the invention are defined in the claims.